TREMMY TREMOLO

[slacker]

Yeah I think 2 LFOs is the way to go for this sort of thing. You can always add the option of running both bits off the same LFO as well if you want. Another thing to try might be mixing the 2 LFOs for proper trippy madness.

Fast chop trem and slow filter/phaser/flanger or whatever is a great combo.

[samhay]

I agree with Ian.
To keep the circuit manageable, you could try buffer each LFO with a transistor rather than another op-amp.

[deadastronaut]

ahhh nice one sam, your a star..

i'll crack on with this as soon as...

i'll rig up 2 lfo's for the ldr's and see how i get on....excellent'e..   (i'll sort a pair of matching ldrs too)

should sound pretty cool...in theory.  

edit: cheers ian...trippy madness is always good..

''Fast chop trem and slow filter/phaser/flanger or whatever is a great combo.'''  yep that's the idea..

[samhay]

^ (i'll sort a pair of matching ldrs too)
I wouldn't bother - they are doing different things, so they don't need matching.

Not sure if you have thought about a depth control for the filter. If not, bear in mind that it will have to work the opposite to the tremolo depth - minimum depth should give minimum current through the LED.

[deadastronaut]

righto...

[duck_arse]

is it tremolo season again? I'm off -over there- doing envelope modulated osc trem, with an ldr even. this thread, however, since the introduction of the triangle and square parts, has me baffled. do you want to have a choppy mixed with a triangle tremolo, or is it some kind of other monster?

[deadastronaut]

other monster...

choppy/smooth trem, with sloowwww 'yearing' filter...option.

[samhay]

An auto-wah-olo?

[duck_arse]

please don't tell me I'm going to have to try this on bb. cause I won't do it.

I won't.

[deadastronaut]

you bloody will....get on with it you lazy ducks buttock.   



: one more lfo to go...had to rearrange my whole breadboard..

[deadastronaut]

hmmmm..

i had a whiney issue so went back to the drawing board....and kept it basic to start.


i breaded the  opamp with filter on its own,(R7 straight to pin 6 (no ldr)  but i just get a whiney tone that changes with light on the filter ldr...

now i know the rest of it is ok, as a test i  tried it without the filter and stuck a 470k across pins 1 and 2 instead to make sure i get a good clean unity signal...which it does nicely..

as soon as i put the twin t section back on....whooooooooeeeeeeeeeoooooooohwww..weird. more like a tone generator..

[samhay]

So the op-amp twin-T filter isn't working right? I haven't breadboarded it, but it looks like it should work ok.
What are the light and dark resistances of your LDR?

[deadastronaut]

Hi Sam , 22k to 2000. ....ish.

yeah looks like it should be ok, worked with a 470k across pin 1 &2...hmmm.


edit: ok.stuck a 470k across pins 1/2 with the filter...now it works.  ...which is strange as there is 2x220ks across it anyway...weird..

(still get that led noise with distortion with guitar rolled off....hmmmm....but hey its working ok now...

[samhay]

^stuck a 470k across pins 1/2 with the filter...now it works

Have you made a bridge-T filter? (http://www.geofex.com/article_folders/eqs/paramet.htm, bottom of the page)

[deadastronaut]

yeah, as you drew it, but added the 470k too works fine now...

just cleared of another breadboard to put the other lfo on....

now we can just lift one side of the filter like before to turn it off...cool.

i'll tweak the filter values a little ....

the depth would be mad on lfo too..sounds quite sick, but getting into synth territory there...but i had to try it..

got a few chores to sort..then i'm, back on it. 

[Mark Hammer]

Have we ever tinkered with hypertriangular LFOs for tremolo here?  I'm just wondering if it represents a useful addition to the assorted waveforms, even if only for a narrow range of modulation rates.  I've never heard a hypertriangular LFO in action w/tremolo so I don't know if it sounds nice, sounds the same as triangle, or sounds unappealing.

For example, consider the analog portion of this circuit (i.e., everything up to the modulation depth control): http://hammer.ampage.org/files/hypertriangleclock.gif (I'd insert it in the post but it's disconcertingly big)

[duck_arse]

I messed up an oscillator with some sorta hyper thingy. one knob twists from triangle/sine-ish to sine-ish to sine-ish/triangle. one of the first circuits I posted here. looks like this:

http://www.diystompboxes.com/smfforum/index.php?topic=98974.msg886084#msg886084

[Mark Hammer]

Thanks.  I look forward to being able to see it later this evening (work filters...bah!).

[deadastronaut]

ok, got my 2 lfo's going...after faffing around with mrs astronaut, she came home with a massive old 1930's wills's cigarettes enamel sign (which she collects) she bought it from some dumbass in a shop for £15.00, and its worth £350.00,

i spent today t-cutting it, and its come up lovely...very cool...anyway nevermind that.....

like a dumbass i recorded this clip and then realized i had the lfo's swapped...e.g, the square /triangle was on the filter not the trem...

anyway..i'll sort that, but its sounding promising....   will be much better when i swap lfo's..

https://dl.dropboxusercontent.com/u/7464107/filtremolo.mp3

[haveyouseenhim]

My face has been melted. Dude, you have to stop with these amazing effects. I can't keep up!